In Nanoha, 21 Jewel Seeds are scattered across Earth (primarily Japan and the Western Pacific Ocean) following an interdimensional transport accident, corrupting the local life forms and attracting attention of several powerful mages; The MOVIE 1st additionally implies that Presea Testarossa orchestrated this "accident". The first one to attempt to recover the Jewel Seeds is the Midchildan archeologist Yuuno Scrya, but he is wounded by the monster spawned by Seed XXI and has to rely on a local, Nanoha Takamachi, to recover the rest while he recuperates. Meanwhile, Presea sends her daughter Fate Testarossa to collect the Seeds for her own purposes. Nanoha and Fate clash over the remaining Seeds until they are interrupted by the agents of the Administrative Bureau, who arrive to Earth to secure the Lost Logia before they can cause a dimensional rift. Between these three parties, all Seeds are located and sealed by the end of the season.

A typical sealing chant for a Jewel Seed, used for most of season 1, would be "Jewel Seed Serial XIV! Seal It!", with "XIV" being replaced with the number of whatever Seed was being sealed at the time.

In episode 4, Fate seals and claims an unidentified Seed, which she delivers to her mother Precia along with others in episode 7.

In episode 5, Fate steals one of the Seeds Nanoha has previously captured and delivers it to Precia in episode 7. Its number is never mentioned.

In episode 9, Fate raises six Seeds from the depths of the Pacific Ocean, which are never identified by number. Three of these are claimed by Chrono for the Bureau and the other three, by Arf for Precia Testarossa.

Thus, Presea Testarossa possessed nine Jewel Seeds at the time of her disappearance, which presumably went missing along with her and Alicia's body.[2] The remaining twelve were probably taken into custody by the Bureau, and at least some of them were stolen by Jail Scaglietti in the following decade.[3]